Exhaust manifold heat valve control system

ABSTRACT

An exhaust heat valve control system for an internal combustion engine in which the position of the heat valve is dependent on the carburetor flange temperature. A temperature responsive bimetal valve opens and closes a vent to a vacuum chamber in response to the carburetor flange temperature. A vacuum motor connected to the vacuum chamber displaces the exhaust heat valve in response to variations in the vacuum chamber pressures.

mte States mm 1151 3,638,625

Jaimee Feb. l, 1972 [54] EXHAUST MANIFOLD HEAT VALVE 1,821,047 9/1931Wright ..123/122 CONTROL SYSTEM 1,853,623 4/1932 Kirby ..123/1221,944,396 1 1934 B ..123 122 [72] Inventor: Angelo Jaimee, Union Lake,Mich. 2 289 635 7il942 332 23x22 [73] Assignee: Ford Motor Company,Dearborn, Mich.

. Primary Examiner-Laurence M. Goodridge [22] June 1969 AssistantExaminerRona1d B. Cox [21] Appl. No.: 835,369 AttorneyJohn R. Faulknerand Roger E. Erickson 52 us. 01 ..123/122 11, 123/122 AA [57] ABSTRACT[51] llllt. Cl An exhau t heat valve onnsystem for an internal com.

Fleld of Search H, l A, 1 bustion engine in the position of the heatvalve is dependent on the carburetor flange temperature. A temperature[56] References cued responsive bimetal valve opens and closes a vent toa vacuum UNITED STATES PATENTS chamber in response to the carburetorflange temperature. A vacuum motor connected to the vacuum chamberd1sp1aces R6. Molony the exhaust heat valve in response to variations inthe vacuum 3,447,518 5/1969 Walker --.-l/ l7- chamber pressures.1,686,199 10/1928 Bowman..... ...123/122 1,790,469 1/1931 Hans 123/122 2Claims, 3 Drawing Figures PATENTEU FEB I872 QII REBMMQ ATTORNEYS EXHAUSTMANIFOLD HEAT VALVE CONTROL SYSTEM SUMMARY OF THE INVENTION Exhaust andintake manifolds are often cooperatively designed so that the heat ofthe exhaust gases can be used to preheat the air-fuel mixture passingthrough the intake manifold. In such designs the intake manifold has apassage into which exhaust gases are diverted before being dischargedinto the exhaust pipe means. A heat control valve is one device whichcan determine whether the exhaust gases will be discharged directlythrough the exhaust manifold or whether they will be at least partiallydiverted through the intake manifold so as to transfer a portion oftheir heat to the incoming induction mixture.

An exhaust heat valve is conventionally controlled by a bimetal springmounted on or adjacent to the exhaust manifold and is thus responsive tothe temperature of the exhaust manifold.

This invention proposes an exhaust heat valve control system responsiveto temperatures adjacent the carburetor flange or the intake manifold.This system has the advantage of keeping the carburetor flangetemperature more nearly constant, thus reducing undesirable variationsin fuel-air ratios.

An engine carburetor experiences variations in temperatures which arenot experienced by the exhaust manifold. For example, at road speed theair rushing through the carburetor has a refrigerating effect on thecarburetor, thus affecting the fuel-air ratio and making it desirable attimes to add heat to the intake manifold. This invention provides a heatvalve control system which reduces the carburetor temperature rangeduring engine operation.

This invention further provides a heat valve control system whichreduces engine emissions, increases engine efiiciency and is economicalto produce and maintain.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a perspective view of theinvention installed in a V-8 internal combustion engine.

FIG. 2 is an elevational view partly in cross section of the bimetalvalve and the vacuum motor and the exhaust heat valve of the invention.

FIG. 3 is a perspective view of the exhaust heat valve showing theconnection between the vacuum motor and the exhaust heat valve.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT FIG. 1 illustrates a V-8internal combustion engine which includes a preferred embodiment of theinvention. An intake manifold 12 is positioned between the right andleft cylinder heads 13 and 14 and delivers an air-fuel mixture from thecarburetor 16 to the cylinder heads. The intake manifold 12 includes anexhaust crossover passage (not shown) which interconnects selectedexhaust ports of cylinder heads 13 and I4 and routes hot exhaust gasesunder certain conditions under the carburetor heat riser bores (notshown) so as to warm the incoming air-fuel mixture from the carburetor16. Right and left exhaust manifolds 17 and 18 are located on theexterior sides of the cylinder heads 13 and 14, respectively, andinterconnect the exhaust ports of heads 13 and 14 with exhaust pipes 19and 21, respectively.

The carburetor 16 is separated from the intake manifold 12 by a spacer22 which forms a portion of the induction passage. The spacer is locateddownstream of the carburetor throttle valve and thus experiencesessentially intake manifold vacuum pressure. A threaded passage means 23(shown in FIG. 2) extends from the interior of the spacer to itsexterior.

In addition to the conventional engine components described above, theinvention includes a vacuum controlled exhaust heat valve assembly 24, abimetallic vent valve assembly 26 and passage means 27 interconnectingthe two assemblies 24 and 26.

The vent valve assembly 26 includes a sealed housing 28 divided into twocompartments 29 and 31 by a partition wall 32. The lower compartment 29is in communication with the vacuum in the intake manifold 12 viathreaded passage means 23. A second passage means 33 leads from theinterior of the lower compartment 29 to the exterior of the housing. Athird passage means 34 leads from the interior of the upper compartment31 to substantially atmospheric pressure within the interior of the aircleaner 36. A bimetallic element 37 is connected to the partition 32adjacent a port 38 formed in the partition. A generally sphericallyshaped head 39 positioned at the end of the bimetallic element 37functions as a valve member to open and close the port 38 in partition32.

The exhaust heat valve assemble 24, shown in detail in FIGS. 2 and 3,comprises a butterfly valve 41 pivotally mounted within a segment 42 ofthe exhaust passage between the outlet of exhaust manifold 17 and theinlet of exhaust pipe means 19. A spiral-shaped lever arm 43 ispositioned on an endportion of a pivot rod 44 extending through the wallof the segment 42. A bracket 46 interconnects the segment 42 and avacuum motor 47.

The vacuum motor 47 includes a housing 48 having a tubular port 49formed in one end. The interior of the housing is partitioned into twochambers 51 and 52 by a flexible diaphragm 53. Chamber 52 is vented tothe atmosphere. Metal plates 54 are secured to the central portion ofthe diaphragm 53 and have a rigid arm 56 extending perpendicularlytherefrom out of the vacuum motor housing 48 toward the exhaust heatvalve. A second arm 57 is pin jointed to the arm 56 and interconnects itand the lever arm 43 of the exhaust valve. A compression spring 58 ismounted within the housing 48 that tends to increase the volume ofvacuum chamber 51 and to close the butterfly valve 41. A flexible tube27 interconnects the port 49 and the tubular passage 33 of the bimetalvalve assembly, thus constantly communicating the lower compartment 29of the bimetal valve assembly with chamber 51 of the vacuum motor 47.

Installation of the invention on a 6-cylinder engine would be similar tothat described above; however, in an in-line six, the heat valve ispositioned within the exhaust manifold and diverts a portion of the hotexhaust gases around the valve upwardly into and through a heat transferchamber formed within the intake manifold. The exhaust gases return fromthe intake manifold to the exhaust manifold on the opposite side of theheat valve and are discharged into the exhaust pipe means. For example,see US. Pat. No, 1,986,542. Aside from the basic differences of theconventional installation of exhaust heat valves in V-type versusin-line engines, the principles of operation of the invention installedin either type of engine are identical with those described in thefollowing paragraphs.

OPERATION The exhaust heat valve control system described in theforegoing paragraphs functions to open and close the exhaust heat valvein direct response to the engine temperatures adjacent the carburetorflange.

When the carburetor flange temperature is cold, the bimetallic element37 assumes a nearly straight configuration and bead 39 closes port 38 ofthe partition 32. With port 38 so closed, the manifold vacuum from theinterior of the carburetor spacer 22 is communicated through assembly 26to the passage means 27 with no substantial reduction in vacuumpressure. Passage means 27 connects to port 49, whereby chamber 51 alsoexperiences vacuum pressure and assumes a minimum volume position inwhich spring 58 is compressed and arm 56 is withdrawn into the housing48. The withdrawal of arm 56 causes the butterfly valve 41 to close,thereby blocking the outlet to the right exhaust manifold 17. The rightbank exhaust gases are then routed through the crossover passage ofintake manifold 12 and exhaust heat is given up to the carburetor riserbores of the intake manifold and transferred to the incoming air-fuelmixture. The right bank exhaust gases then pass from the intake manifold12 through the left cylinder head 14 and into the left exhaust manifold18.

As the flange of carburetor l6 begins to warm, the bimetal element 37begins to bow causing bead 39 to progressively open port 38. Openingport 38 bleeds the vacuum in passage 27 to substantially atmosphericpressure within chamber 51. Spring 58 expands causing arm 56 to moveoutwardly from housing 48 and to progressively open the butterfly valve41. When the butterfly valve is completely opened, the exhaust gases ofthe right bank of the engine discharge directly through the rightexhaust manifold 17 into exhaust pipe 19. Heat transfer from the intakemanifold 12 to the induction airfuel mixture is reduced accordingly.

The foregoing description presents the presently preferred embodiment ofthe invention. Modifications and alterations will occur to those skilledin the art which are included in the scope and the spirit of theinvention.

lclaim:

1. In an internal combustion engine having a carburetor, an air cleanerfiltering the air prior to entry into the carburetor, intake manifoldmeans receiving anair-fuel mixture from said carburetor, cylinder headmeans receiving said mixture from said intake manifold, exhaust manifoldmeans receiving hot exhaust gases from said cylinder head means, saidintake manifold including a portion in communication with said exhaustmanifold means, and exhaust heat valve means connected to said exhaustmanifold means constructed to divert a portion of the hot exhaust gasesfrom a portion of the exhaust manifold means to the intake manifoldmeans to heat the incoming air-fuel mixture,

said heat valve means including a pivotally mounted butterfly platewhich opens and closes a portion of said exhaust manifold means,

vacuum motor means having a movable portion connected to said butterflyplate,

first passage means communicating the vacuum motor means with a sourceof vacuum pressure,

second passage means communicating said first passage means with theinterior of said air cleaner,

bimetallic valve means in said second passage means adjacent saidcarburetor and said intake manifold, said bimetallic valve meansincluding a movable portion constructed to open and close said secondpassage means in response to carburetor temperature.

2. In an internal combustion engine having a carburetor, intake manifoldmeans receiving an air-fuel mixture from said carburetor, cylinder headmeans receiving said mixture from said intake manifold exhaust passagemeans including exhaust manifold means receiving and transporting hotexhaust gases from said cylinder head means, said intake manifoldincluding a portion in communication with said exhaust manifold means,

and exhaust heat valve means in said exhaust passage means constructedto divert a portion of the hot exhaust gases from a portion of theexhaust manifold means to the intake manifold means to heat the incomingair-fuel mixture,

said heat control valve means including a pivotally mounted butterflyplate to open and close a portion of said exhaust passage means,

vacuum motor means having a spring biased movable portion connected tosaid butterfly valve, first passage means communicating the intakemanifold adjacent said carburetor and said vacuum motor means,

second passage means communicating said atmospheric air compartment withthe interior 'of said air cleaner assembly,

vacuum control means adjacent said carburetor and intake manifoldcomprising a housing having a vacuum compartment and an atmospheric aircompartment,

said vacuum compartment comprising a portion of said first passagemeans,

ableed vent between said compartments, temperature responsive valvemeans within said vacuum compartment movable in response to changes incarburetor and intake manifold temperatures, said valve means comprisinga bimetal element secured at one end to a wall of said compartment andat the other end having a bead,

said bead received within and restricting said bleed vent during enginewarmup temperatures,

said bead being removed from said bleed vent during normal operatingtemperatures of said engine,

whereby the removal of the bead from said bleed vent decreases thevacuum pressure acting on the vacuum motor causing the heat controlvalve means to open and reduce the heating effect of exhaust gases onthe intake manifold.

1. In an internal combustion engine having a carburetor, an air cleanerfiltering the air prior to entry into the carburetor, intake manifoldmeans receiving an air-fuel mixture from said carburetor, cylinder headmeans receiving said mixture from said intake manifold, exhaust manifoldmeans receiving hot exhaust gases from said cylinder head means, saidintake manifold including a portion in communication with said exhaustmanifold means, and exhaust heat valve means connected to said exhaustmanifold means constructed to divert a portion of the hot exhaust gasesfrom a portion of the exhaust manifold means to the intake manifoldmeans to heat the incoming air-fuel mixture, said heat valve meansincluding a pivotally mounted butterfly plate which opens and closes aportion of said exhaust manifold means, vacuum motor means having amovable portion connected to said butterfly plate, first passage meanscommunicating the vacuum motor means with a source of vacuum pressure,second passage means communicating said first passage means with theinterior of said air cleaner, bimetallic valve means in said secondpassage means adjacent said carburetor and said intake manifold, saidbimetallic valve means including a movable portion constructed to openand close said second passage means in response to carburetortemperature.
 2. In an internal combustion engine having a carburetor,intake manifold means receiving an air-fuel mixture from saidcarburetor, cylinder head means receiving said mixture from said intakemanifold exhaust passage means including exhaust manifold meansreceiving and transporting hot exhaust gases from said cylinder headmeans, said intake manifold including a portion in communication withsaid exhaust manifold means, and exhaust heat valve means in saidexhaust passage means constructed to divert a portion of the hot exhaustgases from a portion of the exhaust manifold means to the intakemanifold means to heat the incoming air-fuel mixture, said heat controlvalve means including a pivotally mounted butterfly plate to open andclose a portion of said exhaust passage means, vacuum motor means havinga spring biased movable portion connected to said butterfly valve, firstpassage means communicating the intake manifold adjacent said carburetorand said vacuum motor means, second passage means communicating saidatmospheric air compartment with the interior of said air cleanerassembly, vacuum control means adjacent said carburetor and intakemanifold comprising a housing having a vacuum compartment and anatmospheric air compartment, said vacuum compartment comprising aportion of said first passage means, a bleed vent between saidcompartments, temperature responsive valve means within said vacuumcompartment movable in response to changes in carburetor and intakemanifold temperatures, said valve means comprising a bimetal elementsecured at one end to a wall of said compartment and at the other endhaving a bead, said bead received within and restricting said bleed ventduring engine warmup temperatures, said bead being removed from saidbleed vent during normal operating temperatures of said engine, wherebythe removal of the bead from said bleed vent decreases the vacuumpressure acting on the vacuum motor causing the heat control valve meansto open and reduce the heating effect of exhaust gases on the intakemanifold.